Pivotal door check device



July 3, M CARLSON PIVOTAL' DOOR CHECK DEVICE Filed Feb. 26, 1953 PIV @TAL DOR CHECK DEVICE Martin Carlson, Brookfield, lli., assigner to George W. Houisby, Jr., Chicago, 1li.

Application February 26, 1953, Serial No. 339,006 3 Claims. (Cl. 16-55) The present invention relates to door checks, and more particularly to door check devices adapted to serve also as pivotal door mounts.

One object of the invention is to provide an improved door check device of the above type having a novel organiaztion of coacting mechanical elements which minimizes the manufacturing costs of the device.

A further object is to provide a pivotal door checl: of a simplied construction which provides an improved movement controlling action for a door while minimizing operational friction.

Other objects and advantages will become apparent from the following description of the exemplary form of the invention shown in the drawing, in which:

Figure l is a vertical, sectional View of a door check device embodying the invention and illustrating the manner in which the device serves as a pivotal mount for a door;

Fig. 2 is a horizontal sectional view of the check device taken along line 2-2 of Fig. l; and

Fig. 3 is a fragmentary view taken generally along line 3 3 of Fig. 2 and showing an end view of the swingable cam follower.

While certain advantages are realized from the specific correlation of structural elements forming the illustrated embodiment of the invention, it will be appreciated that the invention is not necessarily limited to the precise form shown but includes all equivalent constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring to the drawing in greater detail, the door check embodying the present invention is adapted to serve also as a pivotal mount for one end (in this instance the lower end) of a door 11. In this respect the structural relationship between the check 10 and the door 11 is generally the same as that shown in my prior Patent No. 2,603,818, issued July 22, 1952.

The mechanisms of the check 10 are contained in a housing 12 set into a casing 14 sunken into the iloor 15, the top of the housing being flush with the floor. A vertical door control and mounting shaft 16 is journaled within the housing 12 to protrude upwardly therefrom along the pivotal axis of a door 11. The upper end of the shaft 16 is non-rotatably joined to the overlying edge of the door 11 in supporting relation thereto. For purposes of illustration the connecting structure between the pivotal check shaft 16 and the door 11 is the same as that shown in my previously mentioned Patent 2,603,818. Reference may be made to the patent for a more detailed description of this connection.

Structurally the housing 12 comprises a dat top plate 17 supported on inwardly projecting flanges 19 near the upper edges of the casing 14 and a deep, generally rectangular pan 20 of rather heavy construction attached to the underside of the plate. The lower end of the pivotal control shaft 16 is journaled by ball bearings 21 in a sturdy support ledge 22 protruding inwardly from one end of the pan 20. A race 24 fixed in the plate 17 in 2,752,627 Patented July 3, 1956 encircling relation to the shaft journals the upper end of the shaft through ball bearings 25 which engage a coacting race formed by an annular flange 26 on the shaft.

A radial main control cam 27 and a radial check cam 29 are fixed in tandem to the shaft 16 between the upper and lower bearings 25 and 21. These cams coact with movable control elements contained within a central support or core 30 attached to the underside of the plate 17 to depend into the central portion of the housing 12.

In prior door check devices of this general type the cam follower assemblies which coact with the main control cams have been relatively expensive to manufacture thus unduly increasing the overall cost of the devices. Moreover, the operation of such conventional door checks has been attended by excessive friction, particularly between the main control cam followers and structural elements coacting therewith.

Such shortcomings of prior door check devices are avoided by the present invention by the use of an improved main cam follower assembly which is inherently susceptible of extremely economical manufacture as well as being substantially free of operational friction. Structurally, the assembly comprises a swingable lever 31 which serves both as a follower for the main control cam 29 and as a guide for a power spring 34 arranged to urge the follower hard against the cam.

Supported at one end by a pivotal connection 35 with the core 30 near one side of the housing pan 20, this multi-purpose lever 31 extends transversely across the housing 12 generally between the core and the cam 27. The opposite or free end of the lever 31 carries a roller 36 positioned to engage the control cam 27. As shown, the lever 31 includes a plate-like shank 37 extending from the pivotal support 35 to a U-shaped head 33 including two forwardly extending, parallel legs 39 that support opposite ends of a journal 40 for the roller 36.

The back side of the lever head 38 is shaped to cleline an indentation 41 which seats the rounded forward end or nose of an elongated pressure member 42 for the spring 34. The rear or tail end of the pressure member 42 extends loosely through a spring seat 44 formed by an adjustable sleeve threaded into a support 45 projecting laterally from the core 30. Coiled around the pressure member 42 the spring 34 reacts on the seat 44 to press against a collar 46 fixed to the pressure member 42. The strong biasing force of the spring 34 is transmitted through the pressure member 42 to the follower lever 31 which, in turn, serves as a guide for the spring.

This entire follower assembly is extremely economical to fabricate. The loose fit between the tail end of the spring pressure member 42 in the spring seat sleeve 44 permits these parts to be inexpensively fashioned with virtually no regard to manufacturing tolerances. The pressure member 42 itself is an inexpensive item. The follower lever 31 is a simple element that may have a very rough construction. Provision for the abutting action of the pressure member 42 on the back side `of the lever 31 can be made virtually without cost. The pivotal support 35 for the lever 31 can be manufactured without a high degree of accuracy and hence economically fo-rmed. Moreover, it will be appreciated that the correlation of the structure in the control cam follower assembly is such that even very substantial variations in the relative dimensions of the coacting parts will not materially affect the overall action of the assembly in pressing the follower roller 36 hard against the cam 27.

As to the operational friction attending the swinging of the multi-purpose lever 31 toward and away from the shaft 16, it will be appreciated that there are only two noteworthy frictional points. One is at the pivotal support 35 for the lever, and the other is the contact point between the nose of the pressure memberand the lever` However, the vfriction occurring in both these places is very slight for the Vangle of swinging movement of the lever 31 about the pivot 35 is small, so is the degree of relative movement between the pressure member d2 and the lever. As a matter of fact the relative movement at the latter point may approximate a rolling motion with virtually no yfriction included. The `loose fitbetween the pressure member i2 and the spring seat sleeve da avoids any friction between these parts. The rolling friction of the cam following roller 36 isnegligible.

The main control cam 27 has a unique design which cooperates with the follower 31 to provide for an improved control ofthe door 11. in addition to making provision for opening the doorthroug'n 180 further provision is made to yieldably retain the door in either-open or closed position. Further, the cam is designed to coact with the follower to positively prevent closing movement of the door beyond closed door position. Provision is also made for standing the door in various positions beyond its normal open position, without the use of special means to prevent the door from closing.

As to the specific structure involved, the main control cam 27, as shown in Fig. 2, defines an outwardly open closure recess 51 circumferentially located thereon to receive the spring pressed follower roller 36 when the cam is turned by the shaft 16 into closed door position. The cam 27 shown is designed to be rotated counterclockwise, with reference to Fig. 2, upon closing of the door 11. An abrupt stop .surface S2 on the cam 2.7 denes the trailing circumferential extremity of the recess S1 with reference to closing movement of the cam. Engagement of this abrupt stop surface S2 with the follower roller 36 positively terminates closing movement of the cam 27 when the .door 11 has reached fully closed position.

The door 11 is yieldably retained in closed door position by the coaction with the follower roller 36 of a steeply rising cam surface 54 defined by the cam at the side of the recess 51 opposite from the abrupt stop surface 52. However, upon the exertion by a person of a substantial opening force on the door 11, the steep cam surface S4 cams the roller 36 out of the recess 51 onto a gradually rising cam surface 55 constituting a continuation of the steep surface d. As opening movement'of the cam continues, the roller 36 rides along the rising surface 55 rocking the follower 31 away from the shaft 16. if the door 11 is released while the cam follower roller 36 is on the rising cam surface the spring biased action of the follower 31 on this surface will swing the door 11 back to closed position.

To retain the door 11 in open position an open recess 56 is formed in the control cam 27 at a radial angle to the closed recess 51 equal `to the angle at which the door is t'o remain open. For purposes of illustration this angle is approximatciy 130"` Upon engagement of this open recess 56 by the follower roller 36 the cam 27 is retained in open door position until considerable swinging force is applied to the door.

A cylindrical continuation 5'7 of the cam surface beyond thc open recess 56 extends around the cam up to a radial angie of l80 from the closure recess 51. Thus, the door 11 can be opened beyond its normal open position for a total opening movement up to 180. As radial force of the follower roller 36 acting on the cylindrical section 57 of the cam surface creates no turning moment about the shaft i6, the door can be stood at any position beyond its normal open position without the use of special means to prevent its closing. The circumferential portion of the cam 2.7 extending beyond the cylindrical cam surface 57 to the stop surface 52 can be substantially straight as shown or can have any other desired shaping, since it is not ordinarily engaged by the roller 36.

VReturn of the door 11 to closed position is controlled by the coaction of the check cam 29 on the shaft 16 with a hydraulic plunger 59 slidably mounted within a cylinder 6i) defined 'within the core 30. As shown, the end of the plunger 59 adjacent the shaft 16 carries an anti-friction roller 61 which engages a coacting surface 62 on the check cam 29 shaped to force the plunger 59 outwardly in relation to the cam axis as an incident to door closing movement of the pivotal support shaft 16. Conversely, when the shaft 16 is turned by opening movement of the door, the plunger roller 61 follows the cam surface 62 toward the axis of the cam under the force of a follow-up spring 64 acting between the floor of the cylinder 60 and a seat recessed into the bottom of the plunger S9.

It should be noted that the receding contour of the check cam 29 forms the counterpart of the risingcarn surfaces on the main control cam 27. Moreover, a cylindrical continuation 65 of the receding cam surface 62 on the check cam 27 corresponds to the cylindrical portion 57 of the main control cam surface. Thus, when the door 11 is opened to extraordinarily wide positions, the cylindrical surface 65 of the check cam 27 coacts with the plunger rolier 61 to avoid any torsional reaction vof the plunger 59 on the support shaft 16.

Upon extension of the plunger 59 as an incident to opening movement of the shaft 16, the space within the cylinder 6ft behind the plunger is filled with fluid entering the cylinder through a screened check valve 66 screwed into an inlet -iassr/igeway 67 in the bottom of 'the cylinder. A supply of iiuid for this purpose is contained in the housing pau 2d which becomes, in effect, a reservoir.

It will be understood that the check piston follow up spring 64 is relatively weak in comparison to the main control spring 34. The latter overcomes the spring 64 to close the door forcing a retraction ofthe plunger 59. Inward movement of the plunger is slowed by the controlled escapement of oil from the cylinder 60 through two axially spaced outlet orifices 69 and 70, which .open into a passage 71 leading back to the fluid reservoir. During the major portion of the closing movement of the door, fiuid escapes through both of these orifices. However, final closing movement of the door is greatly slowed by a closing of the orifice 69 nearest the shaft 16 by the skirt of the plunger 59, thus allowing escape of oil through only the slow speed orifice 70.

Quick adjustment of the rate of door closing movement of the check 1t) is provided for by an extremely economical arrangement for varying the effective flow area of the orifices 69 and 70. For this purpose, both orifices are located on the top side of the cylinder 64) to be independently adjusted by vertical control needles 72 and 74 threaded into the core 30 and conveniently accessible for adjustment through a hole 79 in the over lying housing plate 17. This hole 'i9 is normally closed by a removable plug '76 threaded into the plate 17.

I claim:

l. A pivotal door check comprising, in combination, a housing, a pivot shaft journaled in said housing, a closure cam fixed to said shaft, a support within said housing, a follower lever pivoted at one end to said support and carrying a follower roller at the opposite end adapted to engage said cam, the free end of -said lever defining an indentation in the back side thereof, apspring scat mounted on said support, an elongated pressure member having its forward ond seated in said follower identation and its rear end loosely guided by said seat, a collar fixed to the forward end of said pressure member, and a power spring coiled about said pressure member and reacting at opposite ends on said seat and said collar to urge said follower hard against said cam.

2. A pivotal door check comprising, in combination, a housing, a pivot shaft journaled in said housing, a closure cam fixed to said shaft, a support within said housing, a follower lever pivoted at one end to said support and carrying a follower roller at the opposite end adapted to engage said cam, the free end .of said lever defining an indentation in the back side thereof, a spring seat mounted on said support, an elongated pressure member Vhaving its forward end seated yin said follower lever indentation and its rear end loosely guided by said seat, a collar fixed to the forward end of said pressure member, a power spring coiled about said pressure member and reacting at opposite ends on said seat and said collar to urge said follower hard against said cam, said cam defining a closure recess therein to re ceive said follower roller when said shaft is turned to closed door position, an abrupt surface defined on said cam at one side of said recess for coacting with said follower roller to prevent door closing movement of said cam beyond said closed door position, said cam defining a rising surface thereon at the side of said recess opposite said abrupt surface for coaction with said follower roller as urged against said cam by said spring to yieldably urge said shaft toward said closed door position, said cam defining an open recess at the outer end of said rising cam surface for coaction with said follower roller as urged against said cam by said spring to yieldably retain said shaft in normal open door position, and a cylindrical surface defined on said cam and extending beyond said open recess to sustain the force of said follower roller thereon without receiving a torsional reaction therefrom upon turning of said shaft beyond normal open door position.

3. A pivotal door check comprising, in combination, a housing, a pivot shaft journaled in said housing, a closure cam fixed to said shaft, a support within said housing, a follower lever pivoted at one end to said support and carrying a cam follower at the opposite end adapted to engage said cam, the cam follower end of said lever dening pivotal connecting means thereon, said support including means defining a spring seat, an elongated pressure member having a forward end pivotally engaging said pivotal connecting means on said follower lever and having its rear end loosely guided by said spring seat means, means mounted on the forward end of said pressure member delining a spring retaining collar, a power spring coiled about said pressure member and reacting at opposite ends on said spring seat and said collar to urge said cam follower hard against said cam, said cam defining a closure recess therein to receive said cam follower upon movement of said cam into closed door position, a rising cam surface defined on said cam at one side of said recess for coaction with said cam follower as urged against said cani by said spring to yieldably urge said shaft into closed door position, said rising cam surface extending from said recess to an outer end at which said cam is engaged by said follower when said shaft is in a normal open door position, and said cam defining a cylindrical cam surface continuing circumferentially beyond the outer end of said rising cam surface to sustain the force of said cam follower without receiving a torsional reaction therefrom upon angular movement of said shaft beyond normal open door position.

References Cited in the file of this patent UNITED STATES PATENTS 850,394 Papenfoth Apr. 16, 1907 2,100,689 Dubonnet Nov. 30, 1937 2,169,336 Best Aug. 15, 1939 2,468,410 Schacht Apr. 26, 1949 2,585,625 Carlson Feb. 12, 1952 FOREIGN PATENTS 7,383 Great Britain May 30, 1837 538,942 Great Britain Aug. 22, 1941 

